<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>OpenLayers: OSM Layer</title>
    <link rel="stylesheet" href="../theme/default/style.css" type="text/css" />
    <link rel="stylesheet" href="style.css" type="text/css" />
    <style>
        #map {
            height: 350px;
        }
    </style>
    <script src="../lib/OpenLayers.js"></script>
    <script type="text/javascript">
        var lon = 5;
        var lat = 40;
        var zoom = 5;
        var map, layer, gml;
        function export_vectors() {
            var x = new OpenLayers.Format.XML();
            var content = x.write(gml.renderer.rendererRoot);
            $("vectors").value = content;
            $("vectors").style.display = "block";
            $("vectorlink").href = "data:image/svg+xml," + escape(content);
            $("vectorlink").style.display="block";
        }
        function on_feature_hover(feature) {
            var text ="<ul>";
            var type ="way";
            if (feature.geometry.CLASS_NAME == "OpenLayers.Geometry.Point") {
                type = "node";
            }    
            text += "<li>" + feature.osm_id + ": <a href='http://crschmidt.net/osm/attributes.html?type="+type+"&id="+feature.osm_id+"'>Edit</a>, <a href='http://www.openstreetmap.org/api/0.5/"+type + "/" + feature.osm_id + "'>API</a></li>";
            for (var key in feature.attributes) {
                text += "<li>" + key + ": " + feature.attributes[key] + "</li>";
            }
            text += "</ul>";
            $("status").innerHTML = text;
        }   
        function clear_data() {
            gml.destroyFeatures();
        }
        function new_data() {
            if (!check_zoom()) { return; }
            clear_data();
            gml.loaded = false;
            gml.url = "http://www.openstreetmap.org/api/0.5/map?bbox=" + map.getExtent().toBBOX();
            $("status").innerHTML = "Loading more data...";
            gml.loadGML();
        }
        function style_osm_feature(feature) {
            feature.style = OpenLayers.Util.extend({'fill':'black'}, OpenLayers.Feature.Vector.style['default']);
            if (feature.attributes.highway == "motorway") {
                feature.style.strokeColor = "blue";
                feature.style.strokeWidth = 5;
            } else if (feature.attributes.highway == "primary") {
                feature.style.strokeColor = "red";
            } else if (feature.attributes.highway == "secondary") {
                feature.style.strokeColor = "orange";
            } else if (feature.attributes.highway) {
                feature.style.strokeColor = "black";
            }   
        }
        function check_zoom() { 
            var zoom = map.getZoom();
            if (zoom >= 11) { return true; }
            if (zoom >= 9) { return confirm("Loading this amount of data may slow your browser. Are you sure you want to do this?"); }
            $("status").innerHTML = "Area too large. Zoom in to load data. (Current zoom level: "+ zoom + ". Must be at zoom 9+.)";
            return false;
        }    
        function init(){
            OpenLayers.ProxyHost = "proxy.cgi?url=";
            OpenLayers.Feature.Vector.style['default'].strokeWidth = 4;
            OpenLayers.Feature.Vector.style['default'].cursor = 'pointer';
            map = new OpenLayers.Map('map', {'maxResolution': 360/512/16, 'numZoomLevels':15, controls: [ new OpenLayers.Control.Navigation(), new OpenLayers.Control.PanZoomBar() ]});
            map.addControl(new OpenLayers.Control.LayerSwitcher());
            map.addControl(new OpenLayers.Control.Permalink());
            layer = new OpenLayers.Layer.WMS( "OSM", 
               [
                 "http://t1.hypercube.telascience.org/tiles?",
                 "http://t2.hypercube.telascience.org/tiles?",
                 "http://t3.hypercube.telascience.org/tiles?",
                 "http://t4.hypercube.telascience.org/tiles?"
                 ], 
                {layers: 'osm-4326', format: 'image/png' } );
            map.addLayer(layer);
            if (!map.getCenter()) { 
                gml = new OpenLayers.Layer.GML("OSM", "osm/sutton_coldfield.osm", {format: OpenLayers.Format.OSM});
                map.zoomToExtent(new OpenLayers.Bounds(-1.819072,52.549034,-1.814341,52.551582));
            } else {
                if (map.getZoom() >= 11) {
                    gml = new OpenLayers.Layer.GML("OSM", "http://www.openstreetmap.org/api/0.5/map?bbox=" + map.getExtent().toBBOX(), {format: OpenLayers.Format.OSM});
                } else {
                    gml = new OpenLayers.Layer.GML("OSM", "xml/cambridgeport.osm", {format: OpenLayers.Format.OSM});
                }    
            }    
            gml.events.register("loadstart", null, function() { $("status").innerHTML = "Loading..."; })
            gml.events.register("loadend", null, function() { $("status").innerHTML = ""; })
            map.addLayer(gml);
            gml.preFeatureInsert = style_osm_feature; 
            var sf = new OpenLayers.Control.SelectFeature(gml, {'onSelect': on_feature_hover});
            map.addControl(sf);
            sf.activate();
        }
    </script>
  </head>
  <body onload="init()">
    <h1 id="title">Advanced OSM Layer</h1>
    <div id="map" class="smallmap"></div>
    <div id="download">
      <ul>
       <li><a href="javascript:new_data();">Download current view</a></li>
       <li><a href="javascript:clear_data();">Clear current data</a></li>
       <li><a href="javascript:export_vectors();">Export Vector Data</a></li>
      </ul>
    <div id="status">Loading...</div>
    </div>
    <a id="vectorlink" href="" style="display:none">Display via data: URL (FF Only)</a>
    <textarea id="vectors" style="display:none;width:100%" rows="10"></textarea>
  </body>
</html>
